Obesity causes various diseases including metabolic syndromes to decrease the ADL and QOL of people. Obesity is a condition that the body fat mass is excessively increased. The number of obesity population is steadily increasing with recent changes in dietary habits, and medical expenses for complications accompanied by obesity are also increasing.
This suggests that early treatment is important, but a marker for predicting early stage of obesity has not been obtained yet.
There are methods using gene polymorphisms for diagnosing obesity. Examples of existing technology relating to such methods include the following Patent Literatures 1 to 4.                Patent Literature 1 discloses detection of a gene encoding a protein selected from PAPPA, PAM, pf20, DNAH11, PKD1, KCNMA1, PKHD1, NRXN3, EPHA7, ROS1, FKSG87, C3orf6, TOX, DLG2, MDS1, FABP2, EFA6R, FLJ20125, Clorf10, CHL1, BICD1, KREMEN1, ADARB2, A2BP1, MGC4309, PIGR, PCSK7, and HSF2 or of a polymorphism closely linked to the gene;        Patent Literature 2 discloses detection of a polymorphism of frizzled-related protein (FRZB) gene;        Patent Literature 3 discloses detection of a polymorphism in a 5′ region of gad2 gene; and        Patent Literature 4 discloses detection of an SNP of ENPP1.        
However, these existing technologies have not been applied to practical use.
The present inventors have performed comprehensive analysis of about fifty thousand single nucleotide polymorphisms (SNPs) present in human genes and investigated correlation with the body fat mass, as disclosed in Patent Literature 5. As a result, it was found that, for example, an SNP (rs491785) in intron 2 of SLC25A24 gene causes a predisposition to obesity.